engineering management and financial ......2020/08/12 · collection from relevant authorities,...
TRANSCRIPT
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MEDRC
PROJECT NO: 12-AS-017
ENGINEERING MANAGEMENT AND FINANCIAL ANALYSIS OF AL FASHKHA SPRINGS DESALINATION
PROJECT
Final Report
Principal Investigator Mohammed Najjar
Birzeit University
Ramallah, West Bank Palestine
The Middle East Desalination Research Center Muscat, Sultanate of Oman
September, 2015
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II
Contents
ABSTRACT ........................................................................................................................................... V
Acknowledgement ................................................................................................................................ VI
Executive Summary .............................................................................................................................. X
List of Abbreviations ............................................................................................................................ X
List of Tables ........................................................................................................................................ XI
List of Figures .................................................................................................................................... XIIII
Chapter One: Introduction .............................................................................................................. 1
1.1 Introduction ..................................................................................................................................... 1
1.2 Statement of the Problem ............................................................................................................... 4
1.3 Research Questions ......................................................................................................................... 4
1.4 Research Objectives ........................................................................................................................ 5
1.5 Significance of the Research........................................................................................................... 5
1.6 Research Approach and Methodology .......................................................................................... 5
1.7 Research Outline ............................................................................................................................. 7
Chapter Two: Study Area of Al Fashkha Springs ..................................................................... 8
2.1. Geography and Topography ........................................................................................................ 8
2.2. Water Resources .......................................................................................................................... 10
2.2.1 Surface Water.................................................................................................................... 10
2.2.2 Groundwater ..................................................................................................................... 12
2.3 Climate ......................................................................................................................................... 15
2.4 Geology and Soil .......................................................................................................................... 16
2.5 Land use ....................................................................................................................................... 18
Chapter Three: Literature Review .............................................................................................. 20
3.1 Desalination Technologies ...................................................................................................... 20
3.1.1 Preface ......................................................................................................................................... 20
3.1.2 Historical Overview ............................................................................................................ 21
3.1.3 Types of Desalination Technologies ................................................................................... 23
3.1.3.1 Membrane and Filtration Processes ...................................................................................... 24
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III
3.1.3.2 Thermal Processes .................................................................................................................. 31
3.1.3.3 Other Desalination Processes ................................................................................................. 36
3.2 Cost of Desalination ...................................................................................................................... 37
3.2.1 Background ......................................................................................................................... 37
3.2.2 Cost of Desalination ............................................................................................................ 38
3.2.2.1 Capital and Operating Costs .................................................................................................. 38
3.2.3 Energy ......................................................................................................................................... 41
3.2.4 Desalination Process Comparison and Choice ................................................................. 42
3.3 Neighboring Regional Desalination Experiences ................................................................. 43
3.3.1 Israeli Experience ................................................................................................................ 43
3.3.1.1 Overview of Israeli Desalination Practices ....................................................................... 43
3.3.1.2 Desalination of Brackish Water ......................................................................................... 44
3.3.1.3 Ashkelon Seawater Desalination Project .......................................................................... 45
3.3.2 Jordan ......................................................................................................................................... 47
3.4 Management of Desalination Projects ....................................................................................... 50
3.4.1 Private Sector Participation (PSP) ........................................................................................ 50
3.4.1.1 Rationale for Private Sector Participation in Desalination Projects ............................ 50
3.4.1.2 Structure of Private Sector Partnership ............................................................................ 51
3.4.1.3 Types of Private Sector Partnership ..................................................................................... 53
3.4.2 Institutional Framework in the Local Water Sector .............................................................. 55
3.4.2.1 The Water Sector Regulatory Council .................................................................................. 56
3.4.2.2 Palestinian Water Authority (PWA) ..................................................................................... 56
3.4.2.3 National Water Company (NWC) ......................................................................................... 56
3.4.2.4 Environmental Quality Authority (EQA) ........................................................................... 577
3.4.2.5 Ministry of Local Government (MoLG) ............................................................................... 57
3.4.2.6 Local Government Units (LGU) ............................................................................................ 57
3.4.2.7 Ministry of Agriculture (MoA) .............................................................................................. 57
3.4.2.8 Ministry of Health (MoH) .................................................................................................... 577
3.4.2.9 Ministry of Finance (MoF) ................................................................................................... 588
3.4.2.10 Palestine Standard Institute (PSI) ....................................................................................... 58
3.4.2.11 Palestinian Central Bureau of Statistic (PCBS) ................................................................. 58
3.4.2.12 Non-Governmental Organizations (NGOs) ........................................................................ 58
3.4.2.13 Water Users Associations (WUAs) ...................................................................................... 58
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IV
Chapter Four: Approach and Methodology .............................................................................. 59
4.1 Research Approach ....................................................................................................................... 59
4.2 Data Collection .............................................................................................................................. 61
4.2.1 Literature Review ...................................................................................................................... 61
4.2.2 Stakeholders Consultation ........................................................................................................ 61
4.3 Analytical Procedures ................................................................................................................... 61
4.3.1 Design of Conveyance System Options for Al Fashkha Springs Desalinated Water .... 62
4.3.1.1 Introduction ............................................................................................................................. 62
4.3.1.2 PWA Strategic Project of Dead Sea Springs .................................................................... 63
4.3.1.3 Conceptual Design of the Proposed Conveyance Systems ................................................... 63
4.3.1.4 Design Criteria and Hydraulic Model ................................................................................... 64
Chapter Five: Results and Discussion ......................................................................................... 67
5.1 Desalinated Water Utilization Options ................................................................................. 67
5.1.1 Option (A) – (Al Fashkha – Jericho) ................................................................................. 67
5.1.1.1 Route Alternative # 1 (A-1) ................................................................................................ 68
5.1.1.2 Route Alternative # 2 (A-2) ................................................................................................ 71
5.1.1.3 Selected Route ..................................................................................................................... 75
5.1.1.4 Calculated Costs .................................................................................................................. 75
5.1.2 Option (B) – (Al Fashkha – Al Ubedeyya) ........................................................................ 76
5.1.2.1 Route Alternative # 1 (B-1) ................................................................................................ 76
5.1.2.2 Route Alternative # 2 (B-2) ................................................................................................ 80
5.1.2.3 Selected Route ..................................................................................................................... 84
5.1.2.4 Calculated Costs .................................................................................................................. 84
5.2 Management Model of Al Fashkha Desalination Project .......................................................... 85
5.2.1 Proposed Management Options ................................................................................................ 85
5.2.2 Proposed Project Model Structure ........................................................................................... 89
Chapter Six: Conclusions and Recommendations .................................................................... 92
6.1 Conclusions .................................................................................................................................... 92
6.2 Recommendations ......................................................................................................................... 95
6.3 Future Research ............................................................................................................................ 96
REFERENCES ................................................................................................................................. 97
ANNEXES ........................................................................................................................................ 102
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V
ABSTRACT Desalination is a fast growing technology that is spreading throughout the world especially in
countries with scarce water resources. Desalination technology offers the potential to convert
the almost infinite supply of seawater and large quantities of brackish groundwater into a new
source of freshwater. Technological advances over the last decades have reduced its cost
dramatically and made it to be a realistic option for increasing water supplies in many areas
around the world having a role in the water management portfolio.
The main objective of this research is to assess the financial feasibility and proposes
management model of the utilization options of the PWA proposed reverse osmosis
desalination project for Al Fashkha Springs which has an overall capacity of desalinating 22
MCM/year. In this research, and after discussion and agreement with PWA, two options of
utilizing the desalinated water have been analyzed including the “Al Fashkha - Jericho” in
Jericho Governorate and “Al Fashkha – Al Ubedeyya” in Bethlehem Governorate.
Al Fashkha springs are located at the north western side of the Dead Sea within a nature
reserve that is under control of the Israeli occupation. Al Fashkha springs have an estimated
volume of water discharged to be around 80 MCM per year which runs eastwards towards the
Dead Sea. During the course of this research work, three water samples were taken from Al
Fashkha springs and were tested at PWA laboratory and gave the following average results:
TDS (2087 mg/l), Salinity (1700 mg/l) and EC (3810 µS/cm). These results show that the
water of Ein Al Fashkha is considered as brackish water.
The overall calculated cost (desalination and conveyance) per cubic meter for the Al Fashkha
– Jericho option is 0.85 $/m3. While for the Al Fashkha – Al Ubedeyya option is 1.06 $/m3.
The BOT agreement is suggested to be adopted for running this project. It is suggested to
be signed between potential consortium of international companies and a government
agency. The agreement is proposed to have a period of 25 years. Construction of the
desalination plant is suggested to go through two phases over 18 months; 11 MCM/year
facility for each. This research has shown that the proposed Al Fashkha Springs Desalination
Project could be a realistic option for PWA to consider in the future as it will create a new
vital water resource that will alleviate the local water supply/demand gap particularly in the
southern West Bank.
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VI
Acknowledgement
I would like to extend my gratitude to everyone who supported me throughout the course of
this thesis research. I am thankful for their aspiring guidance, invaluably constructive
criticism and friendly advice during this research work. I am sincerely grateful to them for
sharing their truthful and enlightening views on a number of issues related to this research.
I express my warm thankfulness to my research supervisor, Dr. Maher Abu-Madi, for your
constant support, direction, dedicated time and patience all along the way to have this
research a recognized piece of knowledge.
Special thanks to my family. Words cannot express how grateful I am to my parents for all of
the sacrifices that you have made on my behalf, and brothers and sisters for being always
around. Your prayer for me was what sustained me thus far. I would also like to thank all of
my friends who supported me in writing, and incented me to strive towards my goal.
Eventually, I extend my appreciation to Dr. Subhi Samhan, Eng. Hazem Kittaneh and the rest
of the Palestinian Water Authority (PWA) team for the support and direction you gave. My
deep thankfulness and appreciation is extended to the Middle East Desalination Research
Center (MEDRC) for the in-kind support in funding this research work.
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VII
Executive Summary
Desalination is a fast growing technology that is spreading throughout the world especially in
countries with scarce water resources. Desalination technology offers the potential to convert
the almost infinite supply of seawater and large quantities of brackish groundwater into a new
source of freshwater. Technological advances over the last decades have reduced its cost
dramatically and made it to be a realistic option for increasing water supplies in many areas
around the world having a role in the water management portfolio.
Palestine as the other countries in the Middle East is suffering from limited and strained
natural water resources, increasing water demand due to increasing rapid population, limited
access to water resources due to the Israeli occupation and its unlimited constraints on the
development of the water sector. Results of previous studies show that the total water needs
in Palestine (municipal, industrial and agricultural) will be around 860 MCM by the year
2020. Current water supply is merely about one-third of that figure and Palestinians should
develop some 550 MCM/Yr additional conventional/non-conventional water resources need
to be developed. This includes groundwater resources, the Jordan River basin, reuse of
treated wastewater, developing desalination plants for brackish and seawater, and considering
water transfer options
The main objective of this research is to assess the financial feasibility and proposes
management model of the utilization options of the PWA proposed reverse osmosis
desalination project for Al Fashkha Springs which has an overall capacity of desalinating 22
MCM/year. In this research, and after discussion and agreement with PWA, two options of
utilizing the desalinated water have been analyzed including the “Al Fashkha - Jericho” in
Jericho Governorate and “Al Fashkha – Al Ubedeyya” in Bethlehem Governorate.
The methodology of the research is divided into three main phases. The first phase of
initiating this research was the Concept and Data Collection Phase; mainly consisted of data
collection from relevant authorities, basically from the Palestinian Water Authority (PWA),
including available reports, maps, studies, and the submitted PWA proposal to donor
agencies for establishing the proposed Al Fashkha springs desalination project. Moreover,
literature review work was carried out to develop an understanding of the desalination
technologies, their costs and adopted management models in running such large scheme
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VIII
projects. All available data, reports and literature documents were thoroughly reviewed and
linked together to enable the establishment of a preliminary (inception) report that was
discussed with relevant stakeholders and used as a key document to further proceed in
conducting this research.
The second phase of developing this research was the Data Analysis Phase. In this phase the
description of the existing baseline environmental conditions of the Al Fashkha springs was
developed in support of creation of visual GIS maps representing the different environmental
aspects of the area using ArcGIS 10.1 program. Then the process of proposing and laying out
conceptual design for the conveyance systems of the desalinated water from Al Fashkha
springs that was done in constant stakeholder consultation mainly with PWA and the
Ministry of Agriculture (MoA) to identify the direct beneficiary communities from this
proposed project. After setting out the conceptual designs, detailed hydraulic designs were
developed with more than once option using the Water CAD V8i software program that was
companied with conducting costing analysis for the proposed options to account for the
capital and operational costs of each option.
On the other hand, along with the technical work done to establish the engineering designs
and their costs, another analysis was done to establish management framework for
establishing and running such a non-conventional large scheme project that was done in
direct consultation with relevant authorities and stakeholders. This work investigated
available scenarios to run such a project and the development of the possible management
models was done.
The third and last phase of finalizing this research was the Decision Analysis phase. In this
phase the selection of the desalination technology and the conveyance system for the
desalinated water associated with its capital and running costs was done after evaluating the
developed options. Moreover, the management framework for the project was set out and
finalized.
Al Fashkha springs are located at the north western side of the Dead Sea within a nature
reserve that is under control of the Israeli occupation. Al Fashkha springs have an estimated
volume of water discharged to be around 80 MCM per year which runs eastwards towards the
Dead Sea. During the course of this research work, three water samples were taken from Al
Fashkha springs and were tested at PWA laboratory and gave the following average results:
TDS (2087 mg/l), Salinity (1700 mg/l) and EC (3810 µS/cm). These results show that the
water of Ein Al Fashkha is considered as brackish water.
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IX
The overall calculated cost (desalination and conveyance) per cubic meter for the Al Fashkha
– Jericho option is 0.85 $/m3. While for the Al Fashkha – Al Ubedeyya option is 1.06 $/m3.
The BOT agreement is suggested to be adopted for running this project. It is suggested to be
signed between potential consortium of international companies and a government agency.
The agreement is proposed to have a period of 25 years. Construction of the desalination
plant is suggested to go through two phases over 18 months; 11 MCM/year facility for each.
This research has shown that the proposed Al Fashkha Springs Desalination Project could be
a realistic option for PWA to consider in the future as it will create a new vital water resource
that will alleviate the local water supply/demand gap particularly in the southern West Bank.
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X
List of Abbreviations
km² Square kilometer
km Kilometer
m Meter
mm Millimeter
mm/yr Millimeter per year
mbsl Meter below sea level
masl Meter above sea level
L L iters
l/c/d Liters per capita per day
MCM Million cubic meters
MCM/yr Million cubic meters per year
m3/d Cubic meter per day
$/m3 US dollar per cubic meter
mg/l Milligram per liter oC Celsius degrees
NIS New Israeli Shekel
PSI Palestine Standards Institute
PWA Palestinian Water Authority
JWU Jerusalem Water Undertaking
WBWD West Bank Water Department
MoA Ministry of Agriculture
MoLG Ministry of Local Government
MoH Ministry of Health
EQA Environment Quality Authority
NWC National Water Company
WUA Water Users Association
GIS Geographic Information System
TDS Total Dissolved Solids
EC Electrical Conductivity
RO Reverse Osmosis
BOT Build Operate Transfer
PPP Public Private Partnership
EPC Engineering and Procurement Contract
O&M Operation and Maintenance
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List of Tables
Table (2-1): Flow Contribution to the Dead Sea Basin…………………………………………….. 11
Table (2-2): Results of Ein Al Fashkha Water Samples ....................................................................... 15
Table (3-1): Advantages and disadvantages of Electrodialysis technology ......................................... 27
Table (3-2): Advantages and Disadvantages of Reverse Osmosis technology ..................................... 31
Table (3-3): Advantages and disadvantages of Multi-Stage Flash desalination technology………….35
Table (3-4): Advantages and disadvantages of Multi-Effect Distillation desalination technology…….35
Table (3-5): Advantages and disadvantages of Vapor Compression desalination technology ……....39
Table (3-6): Summary of estimation of product water cost components for a large capacity .............. 39
(200,000 m3/d) RO seawater RO plant ................................................................................................ 39
Table (3-7): Desalination Economics .................................................................................................... 41
Table (3-8): Water Cost in Recently Built RO Seawater Plants ........................................................... 41
Table (3-9): Institutional Framework of the Water and Wastewater Sector ......................................... 55
Table (5-1): Selected Pump Schedule - Option (A-1) ........................................................................... 69
Table (5-2): Cost Estimations of the Conveyance System Components of Option (A-1) .................... 70
Table (5-3): Estimations of Pumping Costs of Option (A-1) ................................................................ 71
Table (5-4): Selected Pump Schedule - Option (A-2) ........................................................................... 72
Table (5-5): Cost Estimations of the Conveyance System Components of Option (A-2) .................... 74
Table (5-6): Estimations of Pumping Costs of Option (A-2) ................................................................ 74
Table (5-7): Selected Pump Schedule - Option (B-1) ........................................................................... 78
Table (5-8): Cost Estimations of the Conveyance System Components of Option (B-1) .................... 79
Table (5-9): Estimations of Pumping Costs of Option (B-1) ................................................................ 80
Table (5-10): Selected Pump Schedule - Option (B-2) ......................................................................... 81
Table (5-11): Cost Estimations of the Conveyance System Components of Option (B-2) .................. 83
Table (5-12): Estimations of Pumping Costs of Option (B-2) .............................................................. 84
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List of Figures
Figure (1-1): Worldwide Desalination Capacity in 2006………………………………………………2
Figure (1-2): Desalination Process Schematic………………………………………………………….2
Figure (2-1): Location Map of the Study Area ....................................................................................... 8
Figure (2-2): Satellite Image of the Study Area ...................................................................................... 9
Figure (2-3): Topographic Map of the Study Area ............................................................................... 10
Figure (2-4): Surface Catchments Situated in the Study Area .............................................................. 11
Figure (2-5): Basin Map for the study Area .......................................................................................... 12
Figure (2-6): Discharge of Dead Sea Springs ....................................................................................... 14
Figure (2-7): Rainfall Contour of the Study Area ................................................................................. 16
Figure (2-8): Geological Map for the study Area ................................................................................. 18
Figure (2-9): Soil Map for the study Area ............................................................................................ 18
Figure (2-10): Land use of the Study Area.. ......................................................................................... 19
Figure (3-1): Annually contracted desalination capacity (on the left). Cumulative contracted and operated desalination capacity (on the right)…………………………………………………………………………………… 22
Figure (3-2): Basic illustration of membrane processes ....................................................................... 24
Figure (3-3): Schematic of an Electrodialysis Stack ............................................................................. 26
Figure (3-4): Stack of Electrodyalisis Cells .......................................................................................... 26
Figure (3-5): Electrodialysis Cell……………………………………………………………………………………………………..27
Figure (3-6): Electrodialysis Membrane ............................................................................................... 27
Figure (3-7): RO Desalination Plant flow chart .................................................................................... 28
Figure (3-8): Schematic of a Reverse-Osmosis Desalination Membrane………………………………………….29
Figure (3-9): Multi-Stage Flash Process ............................................................................................... 32
Figure (3-10): Basic illustration of the MED process ........................................................................... 34
Figure (3-11): MED Evaporator Three Effects ..................................................................................... 34
Figure (3-12): Mechanical Vapor Compression schematic .................................................................. 35
Figure (3-13): Cost Analysis of RO Desalination Plants over Years .................................................... 38
Figure (3-14): Cost composition for a typical RO Desalination plant .................................................. 40
Figure (3-15): Sea water RO systems-water sell prices, Capacity10,000-100,000 m3/day .................. 40
Figure (3-16): Desalination technologies applicability with regard to the feed water quality .............. 42
Figure (3-17): The annual Israeli production of major desalination plants ........................................... 43
Figure (3-18): The overall annual Israeli production of desalinated water ........................................... 43
Figure (3-19): The Israeli Brackish Water Desalination Program ........................................................ 44
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Figure (3-20): Cost of desalinated water in a number of desalination plants worldwide in comparison to the major Israeli plants ................................................................................................. 43
Figure (3-21): Path towards Private Sector Involvement ...................................................................... 52
Figure (3-22): Overview of the PPP model under a Desalination Project. ........................................... 53
Figure (4-1): Key Steps in the Research Approach Methodology ........................................................ 60
Figure (5-1): Al Fashkha – Jericho Option, Alternative Route #1 (A-1) .............................................. 68
Figure 5-2: Performance or Characteristic Curve of the Selected Pump - Option (A-1) ...................... 69
Figure (5-3): Al Fashkha – Jericho Option, Alternative Route #2 (A-2) .............................................. 72
Figure (5-4): Performance or Characteristic Curve of the Selected Pump - Option (A-2) ................... 73
Figure (5-5): Al Fashkha – Al Ubedeyya Option, Alternative Route #1 (B-1) .................................... 77
Figure (5-6): Performance or Characteristic Curve of the Selected Pump - Option (B-1) ................... 78
Figure (5-7): Al Fashkha – Al Ubedeyya Option, Alternative Route #2 (B-2) .................................... 81
Figure (5-8): Performance or Characteristic Curve of the Selected Pump - Option (B-2) ................... 82
Figure (5-9): Authorities and institutions relevant to the management of the Al Fashkha Springs Desalination Project .............................................................................................................................. 88
Figure (5-10): Spectrum of responsibilities in PPP contracts .............................................................. 89
Figure (5-11): Proposed Management Model of Al Fashkha Springs Desalination Project……………….91
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Chapter One: Introduction
1.1 Introduction
Availability of fresh water given the increased demand for water driven by the global
demographic growth, the advancement in the industrial sector, and improvement in the
standards of living is considered a global concern. In many parts of the world the local
demand for water is exceeding the available conventional water resources. The application of
water saving practices and best water management concepts may help in alleviating this
problem but if there is still a shortfall then considering non-conventional water resources
such as desalination of seawater or brackish water may be an option.
Palestine as the other countries in the Middle East is suffering from limited and strained
natural water resources, increasing water demand due to increasing rapid population, limited
access to water resources due to the Israeli occupation and its unlimited constraints on the
development of the water sector. Results of previous studies show that the total water needs
in Palestine (municipal, industrial and agricultural) will be around 860 MCM by the year
2020. Current water supply is merely about one-third of that figure and Palestinians should
develop some 550 MCM/Yr additional conventional/non-conventional water resources need
to be developed. This includes groundwater resources, the Jordan River basin, reuse of
treated wastewater, developing desalination plants for brackish and seawater, and considering
water transfer options (Jayyousi and Srouji, 2009).
Desalination technology offers the potential to convert the almost inexhaustible supply of
seawater and apparently vast quantities of brackish groundwater into a new source of
freshwater. Technological advances over the past 40 years have reduced its cost and have led
to dramatic increases in its use worldwide (The National Academy of Sciences, 2008).
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2
Figure (1-1): Worldwide Desalination Capacity in 2006 (The National Academy of Sciences, 2008)
Desalination is a fast growing technology that is spreading throughout the world especially in
countries with scarce water resources. Desalination is the process of removing salts from
brackish/seawater to provide purified water for industry, irrigation and drinking (HWE, 2009).
Today, desalination is becoming a serious option for the production of drinking and industrial
water as an alternative to traditional surface water treatment and long distance conveyance
(Martin and Rabi, 2009).
Figure (1-2): Desalination Process Schematic (Cooly et al., 2006)
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3
Economics is one of the most important factors determining the ultimate success and extent
of desalination. Desalination’s financial costs, energy demands, environmental implications,
reliability, and social consequences are intertwined with economic issues (Cooly et al., 2006).
The cost of the desalinated water varies according to the desalination technology, the size of
the plant, the salinity of water, and the cost of the energy input to the plant (ACE, 2008).
The capital and operating costs of desalination plants have decreased significantly in real
terms, over the last decades. This is due to several factors, such as process design and
manufacturing improvements, increased competition and privatization (DHV Water et al.,
2004). Such previously mentioned factors made desalination to be a realistic option for
increasing water supplies in many areas around the world, and desalination is gradually
having a role in the water management portfolio. However, the potential of desalination is
constrained by financial, social, and environmental factors (The National Academy of
Sciences, 2008).
Turning towards desalination as a new source of water will play a role in the future planning
and execution of all governments’ tasks in the water sector, including resource assessment and
monitoring, planning and allocation, development and distribution of water and the
mobilization of sector investments. Once a government has determined that it is necessary
to develop a desalination project, the main issue is how this can be realized. High capital
investment and specific high-tech knowledge requirement both of which are scarce in
Palestine could be real challenges. Therefore a realistic option might be to turn towards
the private sector as a provider of both capital and knowledge (DHV Water BV et al., 2004).
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4
1.2 Statement of the Problem
The Palestinian Water Authority (PWA) is developing plans to utilize Al Fashkha springs
(brackish water) for domestic and agricultural uses. This proposal supports the PWA plans
and will further extend the idea to develop a plan to drill wells in the Pleistocene aquifer to
extract brackish water for agricultural use (Aliewi, 2010). Much of the water in the Dead Sea
springs is discharged haphazardly without any real benefit derived to the surrounding
environment. Aimed at utilizing this discharge, this research investigates the utilization of
construction of a desalination plant capable of desalinating the brackish water discharged
from Al Fashkha springs.
The PWA still has not formalized clear options of utilizing the desalinated water from the
proposed project of Al Fashkha springs which entails the establishment of water conveyance
systems for the benefited communities. Moreover, the costs associated with the construction
and operation of this project are considered as main constraint but yet have not been
investigated by PWA. Managing the establishment and operation of such a large scale non-
conventional project would also impose another challenge to PWA to consider.
1.3 Research Questions
This research tries to answer the following questions:
1. What is the available water resource for desalination in Al Fashka springs?
2. What are the proposed utilization options of the desalinated water and their associated
costs?
3. What is the proposed management model for the establishment and running of Al Fashkha
springs desalination project?
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5
1.4 Research Objectives
The aim of this research is to assess the financial feasibility and propose management model
of the utilization options of the proposed PWA desalination project for Al Fashkha Springs.
The specific objectives are:
- To describe the study area of Al Fashkha Springs.
- To conduct financial feasibility for the utilization options of the PWA proposed
desalination project of brackish water at Al Fashkha springs.
- To propose management model for the establishment and operation of future desalination
project of Al Fashkha springs.
1.5 Significance of the Research
This research will be a significant attempt in assessing the financial feasibility and
management model for the proposed Al Fashkha springs desalination project. This study will
contribute to enhancing the knowledge of possible utilizing options of the desalinated water
from Al Fashkha springs and the proposed management model to run this non-conventional
project. The results of this study will provide some insight and information for further
research for Palestinian decision makers and water economists. The study provides a
scientific discussion of concerning costs of utilizing the desalinated water from the future Al
Fashkha springs desalination project and intends to provide useful information on the
proposed management model of this project.
1.6 Research Approach and Methodology
The methodology of the research is divided into three main phases. The first phase of
initiating this research was the Concept and Data Collection Phase; mainly consisted of data
collection from relevant authorities, basically from the Palestinian Water Authority (PWA),
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6
including available reports, maps, studies, and the submitted PWA proposal to donor
agencies for establishing the proposed Al Fashkha springs desalination project. Moreover,
literature review work was carried out to develop an understanding of the desalination
technologies, their costs and adopted management models in running such large scheme
projects. All available data, reports and literature documents were thoroughly reviewed and
linked together to enable the establishment of a preliminary (inception) report that was
discussed with relevant stakeholders and used as a key document to further proceed in
conducting this research.
The second phase of developing this research was the Data Analysis Phase. In this phase the
description of the existing baseline environmental conditions of the Al Fashkha springs was
developed in support of creation of visual GIS maps representing the different environmental
aspects of the area using ArcGIS 10.1 program. Then the process of proposing and laying out
conceptual design for the conveyance systems of the desalinated water from Al Fashkha
springs that was done in constant stakeholder consultation mainly with PWA and the
Ministry of Agriculture (MoA) to identify the direct beneficiary communities from this
proposed project. After setting out the conceptual designs, detailed hydraulic designs were
developed with more than once option using the Water CAD V8i software program that was
companied with conducting costing analysis for the proposed options to account for the
capital and operational costs of each option.
On the other hand, along with the technical work done to establish the engineering designs
and their costs, another analysis was done to establish management framework for
establishing and running such a non-conventional large scheme project that was done in
direct consultation with relevant authorities and stakeholders. This work investigated
available scenarios to run such a project and the development of the possible management
models was done.
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7
The third and last phase of finalizing this research was the Decision Analysis phase. In this
phase the selection of the desalination technology and the conveyance system for the
desalinated water associated with its capital and running costs was done after evaluating the
developed options. Moreover, the management framework for the project was set out and
finalized.
The research approach and methodology are fully discussed in chapter four of this research
thesis.
1.7 Research Outline
This thesis research is comprised of six chapters. Chapter one offers an introduction to the
content and structure of the research, including the statement of the problem, research
questions and objectives. Chapter two describes the different characteristics of the study area
of Al Fashkha springs, providing a briefing of the general environmental characteristics and
water resources of the area. Chapter three, the literature review, discusses the desalination
technologies, their associated costs and available management options in running such large
scheme projects. Chapter four explains the approach and methodology adopted in this
research from purpose of the study to the data collection and analysis phase. Chapter five
provides the results and offers a discussion of the research results. Lastly, chapter six
demonstrates the main conclusions and recommendations formulated as an outcome of this
research.
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Chapter Two: Study Area of Al Fashkha Springs
2.1. Geography and Topography
The study area is considered as a part of Jordan Rift Valley. It is the lowest point on the
surface of the earth about 418 m below mean sea level. The valley slopes gently upward to
the north along the Jordan River and to the south along WadiAraba. It extends from the Red
Sea to Lake Tiberias and beyond with a major 107 km sinistral strike-slip fault between the
Arabian plate to the east and the northeastern part of the African plate to the west. Due to
extensional forces a topographic depression was formed. As a result of an arid environment it
is filled with evaporites, lacustrine sediments, and clastic fluvial components (see Figure 2-1)
(Toll et. al., 2008).
Figure (2-1): Location Map of the Study Area (source: researcher)
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9
The Jordan valley contains one of the richest water resources in the West Bank which is
Fashkha springs. They are located in a nature reserve and archeological site located in the
north-west shore of the Dead Sea(400 m below mean sea level) and about 3 km south of
Qumran wadi.
Figure (2-2): Satellite Image of the Study Area (source: researcher)
Topography is a unique feature of the area; as it changes significantly throughout the area. It
descends gently from attitude of -100 in the west to less than -300 m in the eastwards to Sea
level in the vicinity of Dead Sea (see Figure 2-3).
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10
Figure (2-3): Topographic Map of the Study Area (source: researcher)
2.2. Water Resources
The Jordan Valley contains one of the richest water resources in the West Bank. It grounds
approximately one third of the water reserve in the West Bank and it contains water from the
Jordan River Basin, underground water from the Eastern Aquifer and water flowing into the
Jordan River from the West Bank (PLO, 2011).
2.2.1 Surface Water
Surface water depends mainly on the quantity and duration of rainfall during the wet season.
It mainly includes the Jordan River along with its tributaries and wadis flow from the central
mountains towards the Jordan valley. Table (1) shows wadis that contribute to the Dead Sea
Basin from the West Bank. These wadis are of importance for surface water streams, where
floods from them coincide together to form major streams which rush unchecked fresh
rainwater down to the Dead Sea (Lahlabat, 2013). This source of water is limited Since Israel
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diverted all of the flow of the Upper Jordan River at Lake Tiberias, the Jordan River has been
reduced to a foul trickle (15%) causing a serious decline of 1m/year in the Dead Sea level
(EWASH, 2011).
Table (2-1): Flow Contribution to the Dead Sea Basin (Al Yacoubi, 2007)
Surface Catchment Name Flow (MCM/Year)
Mukallak (Og) 2
Qurman 3.9
Al-Nar 2
Daraja 5.3
Al-Gar 3.4
Abu El Hayyat 0.8
TOTAL 17.4
There are four surface catchments situated in the study area: Marar, Mukallak (Og), Nar, and
Qurman. Fashkha springs are located in Nar Catchments which has a length of 25.78 km and
drains towards the Dead Sea.
Figure (2-4): Surface Catchments Situated in the Study Area (source: researcher)
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2.2.2 Groundwater
The Mountain Aquifer is the main groundwater source in the West Bank. This aquifer is
divided into three sub-basins (The Western Aquifer, the Eastern Aquifer, and the
Northeastern Aquifer). The study area is located in the eastern aquifer (see Figure 2-5) which
has an area of 3,079.5 km2 and mainly consists of carbonate sedimentary rocks with deeply
incised wadis draining to the east (Aliewi, 2007).
In the West Bank, ground water (wells and springs) is considered the main sources of potable
water. The following sections detail the current condition for springs and wells in the study
area.
Figure (2-5): Basin Map for the study Area (source: researcher)
According to available data, there are more than 500 springs located across the West Bank.
The most important of these are located in the Jordan Valley, including the group of springs
located along the western shoreline of the Dead Sea. These springs are considered among the
most important in the West Bank including (PWA, 2002):
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• Fashkha Group Springs
• Turaba spring group
• Ghweir Spring
• Ghazal group springs
• Tanur Spring
Located within the West Bank (see Figure 2-4), the Dead Sea Springs serve as a final
southeastern outlet for the Eastern Basin, and have an estimated annual flow of 100-110
million cubic meters of brackish water, which runs eastwards towards the Dead Sea (PWA,
2002).
In the West Bank the renewable water can be estimated to be 760 MCM where 10% of this
quantity can be considered brackish water (HWE, 2009). Brackish water is basically
concentrated in the Jordan Valley. According to Palestinian Water Authority (PWA) records
and studies, brackish water in Jordan valley could reach up to 80 million cubic meters. This
quantity is basically used for agriculture and drinking. Those 80 MCM could be considered in
planning a new desalination plant (HWE, 2009).
The main amount of brackish water located in the Jordan valley can be found in Al Fashkha
springs group; which is composed of ten springs within close proximity to each other, the
volume of water discharged by these springs could be around 70 to 100 MCM per year
(HWE, 2009).
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14
Figure (2-6): Discharge of Dead Sea Springs (Abdelghafour, 2009)
Historical Records show that the Dead Sea springs flow ranges from 70-80 MCM/y, while
recent records show that the flow ranges from 90-117 MCM/y (Abdelghafour, 2009).
Available records show that some of the Dead Sea springs, such as Fashkha and Tannur
Springs, have relatively high values of Total Dissolved Solids (TDS) ranging from 1,500 to
5,000 mg/l and making them brackish, as well as a high content of chloride and other
constituents (PWA, 2002).
The water quality of these springs largely depends on the surrounding geological regime. In
particular, the main source of salinity affecting the springs are the saline layers deposited
along the shoreline of the Dead Sea, through which fresh groundwater passes as it emerges to
the surface. As such, salinity levels vary according to the degree of solubility, though more
data is needed on the water quality of the Dead Sea Springs, after which further studies into
salinity levels can be carried out (PWA, 2002).
Water samples were taken from the Ein Al Fashkha springs during a site visit done by the
researcher and were measured for salinity, TDS and electric conductivity (EC) at the PWA
labs using Jenway digital meter. The results obtained are shown in table (2-2) and all are
within the ranges of the brackish water.
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15
Table (2-2): Results of Ein Al Fashkha Water Samples
TDS (mg/l) Salinity (mg/l) EC (µS/cm)
Sample # 1 2010 1700 3700
Sample # 2 2120 1700 3860
Sample # 3 2130 1700 3870
Average 2087 1700 3810
Standard Ranges For
Brackish Water
1000-10,000* 1000-3000* TDS = 0.6 EC**
(conversion factor)
*(McKinney, D.C., 2014)
** (Al-Motaz, I. S., 2014)
2.3 Climate
In general, the climate of the Jordan Valley is Mediterranean in its basic pattern, it is
characterized by arid to semi-arid climate which are dominated by low annual rainfall, low
soil moisture conditions and very high potential evapotranspiration levels. The study area has
hot dry summer and warm low rain winter. The temperature varies from high temperature in
the south that slightly decreases further to the north. The average temperature is about 40 °C
in summer and about 15 °C in winter. The winds are generally from the west and southwest,
coming from the Mediterranean Sea, and have a moderating influence in the summer
weather. Occasional winds coming from the south and east over the desert are cold and dry in
the winter, and dusty and scorching in the spring. The study area is characterized by low
amount in rainfall. The amount of rainfall decreases eastwards with rainfall gradient changes
from more than 150 to less than 100 mm/year in the vicinity of the Dead Sea. The mean
annual rainfall is approximately 100 mm/year (see Figure 2-7), of which approximately 60%
falls in the three months of December, January and February.
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Figure (2-7): Rainfall Contour of the Study Area (source: researcher)
2.4 Geology and Soil
In the Jordan Valley, approximately, 28% of it is composed of Coniacian-Camparian and
Camparian Chalk and Chert formations, 27% is composed of Turonian and Cenomanian
limestone, marl and dolostone formations while 16% is composed of Sandstone, siltstone,
dolostone and limestone formations. Dolostone, clay, sand loess and gravel make up the
remaining 29%.
Fashkha springs group area is mainly composed of continental sediments of quarternary age
(see figure 8). These constitute clastic (clay, sand and gravel) deposited in fan deltas with
some intercalations of lacustrine sediments (clay, gypsum and aragonite) of the lisan
formation and younger holocenic sediments (Hasan, 2009).
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Figure (2-8): Geological Map for the study Area (source: researcher)
The soil depth varies widely along depending on surface geology and vegetation density. In
the Jordan Valley; the main rock type are Lisan marls. They are deposits of a former inland
lake and consist of loose diluvial marls. The Lisan marl soils are generally of a rather light
nature, their clay content varies from approximately 10 to 20%. High concentration of lime
content is present, which varies between 25 and 50%. Where there is no possibility for
irrigation, the Lisan marls are covered with a very sparse growth of halophytic plants. In the
Eastern Slopes region, the main soil types are the semi-desert soils, the secondary soil types
are the mountain marls. For the semi-desert soils, the formation of sand and gravel is
characteristic of desert weathering (Hasan, 2009).
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Figure (2-9): Soil Map for the study Area (source: researcher)
2.5 Land use
Al Fashkha springs are located in an area under the Israeli control which is considered as
natural reserve area surrounded by closed rang Israeli military areas that is not utilized for
any purposes. The lands surrounding the springs area are mainly covered by shrub plants.
The natural reserve of Ein Al Fashkha is considered as the lowest natural reserve in the world
and is managed by the Israeli Nature and Parks Authority (Wikipedia, 2015). The reserve is
divided into three sections; the northern section which is called the “closed reserve” and has
an area of 2,700 donums. This section is closed to the public and used by scientists and
researchers. The central section, which is called the “visitors reserve”, is open to the public
and features a series of pools for swimming filled with natural spring water and has an overall
area of 500 donums. The southern section, which is called the “hidden reserve”, has an area
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of 1,500 donums and open to the public only when visiting on an organized group tour or a
specially licensed private tour guide (INPA, 2015). Photos taken by the researcher of the Ein
Fashkha springs reserve are provided in Annex (A).
Figure (2-10): Land use of the Study Area (source: researcher)
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Chapter Three: Literature Review
3.1 Desalination Technologies
3.1.1 Preface
Amongst all of our planet’s water, 97.5% is salt water from the oceans and about 2.5% is
fresh. More than two thirds of the fresh water is underground and the rest exist in glaciers
(The National Academy of Sciences, 2008). Given that sea water has commercial importance in
supporting the mankind’s life such as; sea trade, transport and fishing, but it has limited use
in the domestic and agricultural sectors which are vital sectors to support the human life.
Fresh water scarcity has led in different parts of the world to develop options and
technologies to utilize the non-fresh water resources (brackish and saline) particularly by
removing the dissolved salts from them through the process of desalination to allow for
developing and utilizing new non-conventional water resources that can be added to the
available conventional water resources.
Ongoing increased demand for fresh water is considered a global concern. Across the world,
the water demand is higher than the available conventional water resources. Applying water
saving practices, improving the water supply systems and increasing the use of recycled
water may have a role in relieving this challenge but when the supply/demand gap keeps
prevailing, then investment in the desalination technologies could be a strategic option.
Today, desalination is becoming a serious option for the production of drinking, agricultural
and industrial water as an alternative to traditional surface water treatment and long distance
conveyance. In some countries, desalination has long been confined to situations where no
other alternatives were available to produce drinking water (some coastal towns, islands,
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remote industrial sites, etc.), or where energy is abundantly available (power stations, gas and
oil production fields) (Martin and Rabi, 2009).
Recent technological advances have made removing salt from seawater and ground
(brackish) water a realistic option for increasing water supplies in many areas around the
world, and desalination is gradually having a role in the water management portfolio.
However, the potential of desalination is constrained by financial, social, and environmental
factors. Substantial uncertainties remain about its environmental impacts and financial
viability, which have led to delays in its application. A coordinated, strategic research effort
with steady funding is needed to better understand and minimize desalination’s
environmental impacts—and to find ways to further lower its costs and energy consumption
(The National Academy of Sciences, 2008).
This section discusses the various seawater/brackish water desalination technologies. These
technologies are constantly being improved and enhanced in terms of economical,
technological and sustainable perspectives.
3.1.2 Historical Overview
The late decades of the nineteenth century had a dramatic evolution in the application of
desalination technologies in different parts of the world particularly; in the regions that suffer
from shortfall of precipitation and availability of fresh water resources such as: the Pacific
and Caribbean islands, north Africa and the middle east (AFFA, 2002).
The application of the desalination technologies was intensively developed after the end of
the World War II. Commercial application of thermal/distillation desalination technologies
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were predominant in the 1960’s – 1970’s. While through the period of 1980’s and 1990’s the
development of the membrane desalination technologies was dramatically experienced and
introduced to the global market on a commercial scale which were noticeable cheaper and
easier in application (AFFA, 2002).
This growth of the investment in the desalination technologies is shown in figure (3-1).
Figure (3-1): Annually contracted desalination capacity (on the left). Cumulative contracted and
operated desalination capacity (on the right) (DHV Water BV et al., 2004)
As can be seen from the above figure dated in 2004, 20% of the total global desalination
capacity is produced using membrane processes and currently this proportion is steadily
increasing particularly in the Mediterranean region. Thermal processes dominate the oil-rich
gulf countries in the Middle East (DHV Water BV et al., 2004).
Figure (1-1) in chapter one, shows the worldwide desalination capacity by country which
shows a substantial increment in the desalinated water quantities over time due to the
technological advancement and reduced costs (The National Academy of Sciences, 2008).
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3.1.3 Types of Desalination Technologies
There are a wide range of technologies that have been developed to effectively desalinate
salty water producing water with low concentration of salt (fresh water) and another product
with high concentration of remaining salts (the brine or concentrate). Mainly, these
technologies depend on two major processes to separate salt from the product water;
distillation and filtration via membranes. Ultimately, the selection of a desalination process
depends on site-specific conditions, including the salt content of the feed water, economics,
the quality of water needed by the end user, and local engineering experience and skills
(Cooly et al., 2006).
Desalination is the process of removing salts from brackish/seawater to provide purified
water for industry, irrigation and drinking (HWE, 2009). According to the principles of the
processes used in the desalination technique, the desalination technologies can be classified
into three main categories: (AFFA, 2002):
• Thermal/distillation processes
• Membrane processes
• Chemical processes
Desalination technologies that are based on thermal and membrane processes are the
dominating technologies used for desalinating brackish and seawater on the commercial
scale. Chemical based desalination technologies are used on the smaller scale to end up
producing very high quality water primarily for industrial purposes. (AFFA, 2002).
The following sections investigate the desalination processes that are based on the two main
processes; membrane and thermal processes.
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3.1.3.1 Membrane and Filtration Processes
The main desalination technologies fall under this category are: Reverse Osmosis (RO) which
is a pressure driven technique and Electrodialysis (ED) which is a voltage driven technique.
The ability of the membranes and filters to permit or prohibit the movement of certain ions is
the basic concept behind designing these technologies. These membrane technologies are
considerably efficient in desalinating brackish water. But they have been constantly utilized
for desalinating seawater due to the ongoing enhancement and improvement of the
technology’s reliability and economics. (Cooly et al., 2006)
Figure (3-2) shows the two main membrane and filtration processes used in desalination
(AFFA, 2002).
Figure (3-2): Basic illustration of membrane processes (AFFA, 2002)
Electrodialysis (ED)
“Electrodialysis is an electrochemical separation process that uses electrical currents to move
salt ions selectively through a membrane, leaving fresh water behind” (AFFA, 2002).
Electrodialysis involves the removal of salts by separating and collecting their chemical
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components through electrolysis and is more suited to salty groundwater than seawater (Gold
Coast Water, 2006). ED has relatively high recovery ratios and they are primarily used on
smaller scale capacity in desalinating water for industrial purposes. (Cooly et al., 2006).
“ED works on the principle that salts dissolved in water are naturally ionized and membranes
can be constructed to selectively permit the passage of ions as they move toward electrodes
with an opposite electric charge. Brackish water is pumped at low pressure between stacks of
flat, parallel, ion-permeable membranes that form channels. These channels are arranged with
anion selective membranes alternating with cation-selective membranes such that each
channel has as an anion-selective membrane on one side and a cation-selective membrane on
the other (Figure 3-3). Water flows along the face of these alternating pairs of membranes in
separate channels and an electric current flows across these channels, charging the electrodes.
The anions in the feed water are attracted and diverted towards the positive electrode. These
anions pass through the anion-selective membrane, but cannot pass through the cation-
selective membrane and are trapped in the concentrate channel. Cations move in the opposite
direction through the cation selective membrane to the concentrate channel on the other side
where they are trapped. This process creates alternating channels, a concentrated channel for
the brine and a diluted channel for the product water” (Cooly et al., 2006).
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Figure (3-3): Schematic of an Electrodialysis Stack (Cooly et al., 2006)
“ED membranes are arranged in a series of cell-pairs, which consist of a cell containing brine
and a cell containing product water. A basic ED unit or “membrane stack” consists of several
hundred cell-pairs bound together with electrodes on the outside. Feed water passes
simultaneously in parallel paths through all of the cells to produce continuous flows of fresh
water and brine” (AFFA, 2002).
Figure (3-4): Stack of Electrodyalisis Cells (AFFA, 2002)
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Figure (3-5): Electrodialysis Cell (DHV Water BV et al., 2004)
Table (3-1): Advantages and disadvantages of Electrodialysis technology (AFFA, 2002)
Advantages Disadvantages
• High recovery ratio (85-94% for one stage)
• Can treat feedwater with a higher level of
suspended solids
• Pre-treatment has a low chemical usage
• Relatively high membrane life expectancy (7-10)
years
• Non-susceptible bacterial attack or silica scaling.
• Manual cleaning of membranes
• Low to moderate operating pressure and energy is
proportional to salts removal
• Periodic cleaning of the membranes with
chemicals
• Leaks sometimes occur in the membrane stacks.
• Bacteria, non-ionic substances and residual
turbidity can remain in product water
• Post treatment may be needed
• Primarily used for small scale applications
Figure (3-6): Electrodialysis Membrane (DHV Water BV et al., 2004)
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Reverse Osmosis
Reverse osmosis uses pressure on solutions with concentrations of salt to force fresh water to
move through a semi-permeable membrane (microscopic strainer), leaving the salts behind.
The amount of desalinated water that can be obtained ranges between 30% and 85% of the
volume of the input water, depending on the initial water quality, the quality of the product,
and the technology and membranes involved. (Cooly et al., 2006) This filtering process
removes 95% to 99% of dissolved salts and inorganic material. Reverse osmosis is the finest
level of filtration available and supplies water that is clean, safe, healthy and pleasant to drink
(Gold Coast Water, 2006).
An RO system is made up of the following basic components: pretreatment, high-pressure
pump, membrane assembly, and post-treatment. Pretreatment of feed water is often necessary
to remove contaminants and prevent fouling or microbial growth on the membranes, which
reduces passage of feed water. Pretreatment typically consists of filtration and either the
addition of chemicals to inhibit precipitation or efficient filtering to remove solids. A high-
pressure pump generates the pressure needed to enable the water to pass through the
membrane (Cooly et al., 2006).
Figure (3-7): RO Desalination Plant flow chart (Banat, 2007)
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Figure (3-8): Schematic of a Reverse-Osmosis Desalination Membrane (Cooly et al., 2006)
Membranes may differ in their filtration capacity and they are mainly manufactured in two
configurations; the spiral wound and hollow-fine fiber. The membrane assembly consists of a
pressure vessel and a membrane that permits the feed water to be pressurized against the
semi-permeable membranes. Post-treatment adjusts the pH, removes gases and makes the
product water ready for distribution (Cooly et al., 2006).
The concentration of salts in the feed water is the main determining factor of the required
energy for RO Consequently; RO technology is economically most efficient when
desalinating brackish water(Cooly et al., 2006).
Investment in RO technology has been growing and advances in technology have seen
reverse osmosis become the most popular desalination process used in most parts of the
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world. Improvements in efficiency have led to reduced energy consumption, cheaper
processing costs and a superior product being produced (Gold Coast Water, 2006). Some of
the largest new desalination plants under construction and in operation use RO membranes,
including Ashkelon in Israel and the new plant at Tuas in Singapore (Cooly et al., 2006).
Improvements in the RO technologies are continuously investigated and can be mainly: better
pretreatment of feedwater, enhanced membranes recovery ratios and biofouling resistance,
energy efficiency; cost of membranes materials (Cooly et al., 2006).
Increases in the reliability of reverse osmosis also come from the increased life span of the
membrane. Research indicates that the cost of producing water from a reverse osmosis plant
is often less than half that produced by the distillation method of processing water. Key
parameters for selecting reverse osmosis over other processing methods include (Gold Coast
Water, 2006):
• Quality and salinity of the water intake
• Temperature of water intake
• Efficiency of membranes has improved significantly
• Energy consumption has reduced and is less than other processing methods
• Lower capital and operating costs
• Most major desalination plants now use reverse osmosis
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Table (3-2): Advantages and Disadvantages of Reverse Osmosis technology (AFFA, 2002)
Advantages Disadvantages
• Quick and cheap to build
• Simplicity in operation
• It can handle a large range of flow rates
• Easy expandability and increasing the system
capacity
• High space/production capacity ratio, ranging
from 25,000 to 60,000 L/day/m2.
• Energy consumption is low.
• Contaminants removal
• Low usage of cleaning chemicals
• Simplicity in maintenance
• RO membranes are relatively expensive and have
a life expectancy of 2-5 years.
• It is necessary to maintain an extensive spare
parts inventory.
• There is a possibility of bacterial contamination.
• Pre-treatment of the feedwater is required.
• The plant operates at high pressures
3.1.3.2 Thermal Processes
Thermal desalination processes approximately contributes in total of 40% of the global
desalination capacity. The distillation process mimics the natural water cycle by producing
water vapor that is then condensed into fresh water. In the simplest approach, water is heated
to the boiling point to produce the maximum amount of water vapor (Cooly et al., 2006).
Briefly, Thermal technologies involve boiling saline water and collecting the purified vapor
to produce freshwater after condensation (Gold Coast Water, 2006).
The water boiling degree is directly related to the prevailing pressure, to benefit from this
principle, “multiple boiling” systems have been developed to save energy (Cooly et al., 2006).
Distillation systems are often affected by scaling, which occurs when substances like
carbonates and sulfates1 found in seawater and brackish water precipitate out of solution and
cause thermal and mechanical problems. Scale is difficult to remove and reduces the
effectiveness of desalination operations by restricting flows, reducing heat transfer, and
coating membrane surfaces. Ultimately scaling increases costs. Keeping the temperature and
boiling point low slows the formation of scale (Cooly et al., 2006).
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Multi-Stage Flash Distillation
Multi-stage flash distillation (MSF) is the technology used for the largest installed thermal
distillation capacity. MSF can produce high-quality product water from high salty feedwater.
MSF used to be the primary technology used for desalinating seawater particularly in
countries where the energy cost is not a constraint (Cooly et al., 2006).
“In MSF distillation, water is heated in a series of stages. Typical MSF systems consist of
many evaporation chambers, each with successively lower pressures and temperatures that
cause flash evaporation of hot brine, followed by condensation on cooling tubes. The steam
generated by flashing is condensed in heat exchangers that are cooled by the incoming feed
water. This warms up the feed water, reducing the total amount of thermal energy needed”
(Cooly et al., 2006).
Figure (3-9): Multi-Stage Flash Process (DHV Water BV et al., 2004)
“Generally, only a small percentage of feed water is converted to water vapor, depending on
the pressure maintained in each stage. MSF plants may contain between 4 and 40 stages, but
most typically are in the range of 18 to 25. Multi-stage flash plants are typically built in sizes
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from (10,000 m3/d) to over (35,000 m3/d), with several units grouped together. As of early
2005, the largest MSF plant in operation was in Shuweihat in the United Arab Emirates. This
plant desalinates seawater for municipal purposes with a total capacity of 120 MGD (455,000
m3/d)” (Cooly et al., 2006).
Table (3-3): Advantages and disadvantages of Multi-Stage Flash desalination technology
(AFFA, 2002)
Advantages Disadvantages
• Large handling capacities
• The salinity of the feedwater is not a cost concern
• Very high quality product water (less than 10 mg/L
TDS)
• Minimal pre-treatment requirement
• Long history of commercial use and reliability
• It can be combined with other processes
• Expensive to build and operate
• High level of technical knowledge is required
• Highly energy intensive
• The recovery ratio is low
• The plant cannot be operated below 70-80% of the
design capacity
• Blending is often required when there is less than
50mg/l TDS in the product water
Multiple-Effect Distillation
Over the past century, Multiple-Effect Distillation (MED) which is a thermal desalination
technology has been used successfully. “MED takes place in a series of vessels or “effects”
and reduces the ambient pressure in subsequent effects. There are 8 to 16 effects in a typical
large plant. This approach reuses the heat of vaporization by placing evaporators and
condensers in series. Vapor produced by evaporation can be condensed in a way that uses the
heat of vaporization to heat salt water at a lower temperature and pressure in each succeeding
chamber, permitting water to undergo multiple boiling without supplying additional heat after
the first effect. In MED plants, the salt water enters the first effect and is heated to the boiling
point. Salt water may be sprayed onto heated evaporator tubes or may flow over vertical
surfaces in a thin film to promote rapid boiling and evaporation” (Cooly et al., 2006).
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“Only a portion of the salt water applied to the tubes in the first effect evaporates. The rest
moves to the second effect, where it is applied to another tube bundle heated by the steam
created in the first effect. This steam condenses to fresh water, while giving up heat to
evaporate a portion of the remaining salt water in the next effect. The condensate from the
tubes is recycled” (Cooly et al., 2006).
Figure (3-10): Basic illustration of the MED process (AFFA, 2002)
Figure (3-11): MED Evaporator Three Effects (DHV Water BV et al., 2004)
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Table (3-4): Advantages and disadvantages of Multi-Effect Distillation desalination technology
(AFFA, 2002)
Advantages Disadvantages
• Minimal feedwater pre-treatment requirements
• Product water is of a high quality.
• Very reliable plants
• The plant can be combined with other processes
• The plant can handle normal levels of biological
or suspended matter.
• Minimal operating staff requirements
• Expensive to build and operate
• Energy consumption is particularly high.
• The plant can be susceptible to corrosion
• Cooling of product water is required
• Low recovery ratio
Vapor Compression Distillation
“Vapor compression (VC) distillation has typically been used for small and medium-scale
desalting units. These units also take advantage of the principle of reducing the boiling point
temperature by reducing ambient pressure, but the heat for evaporating the water comes from
the compression of vapor rather than the direct exchange of heat from steam produced in a
boiler. The two primary methods used to condense vapor to produce enough heat to evaporate
incoming seawater are mechanical compression or a steam jet. The mechanical compressor
can be electrically driven, making this process the only one to produce water by distillation
solely with electricity”. VC plants are constructed for small scale capacity such as: small
industries, resorts, remote sites and built in the range of (250 to 2,000 m3/d) (Cooly et al.,
2006).
Figure (3-12): Mechanical Vapor Compression schematic (DHV Water BV et al., 2004)
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Table (3-5): Advantages and disadvantages of Vapor Compression desalination technology
(AFFA, 2002)
Advantages Disadvantages
• Very compact and portable plants
• Minimal pre-treatment requirements
• Reasonable plant capital cost
• Simple and reliable operation
• The recovery ratio is good.
• High quality product water
• Relatively low energy requirements
• Starting up the plant is difficult.
• Smaller scale capacity
• It requires large, expensive steam compressors
• Not readily available spares
“VC units use a compressor to create a vacuum, compress the vapor taken from the vessel,
and condense it inside a tube bundle that is also in the same vessel, producing a stream of
fresh water. As the vapor condenses, it produces fresh water and releases heat to warm the
tube bundle. Salt water is then sprayed on the outside of the heated tube bundle where it boils
and partially evaporates, producing more fresh water. Steam jet-type VC units, also called
thermo-compressors, create lower ambient pressure in the main vessel. This mixture is
condensed on the tube walls to provide the thermal energy (through the heat of condensation)
to evaporate salt water on the other side of the tube walls” (Cooly et al., 2006).
3.1.3.3 Other Desalination Processes
There are a number of other technologies used on the smaller scale to desalinate the brackish
and saline water including but not limited to: ion-exchange resins, freezing, and membrane
distillation. These processes may be more feasible than the other commercial processes under
special site and utilization circumstances (Cooly et al., 2006).
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3.2 Cost of Desalination
3.2.1 Background
Over the history of application of desalination technologies, the perception of the high costs
associated with the establishment and operating desalination schemes limited and even
prevented the utilization of desalination technologies as an alternative in providing new water
resource in different areas around the world. Nowadays, the perception towards the
desalination technologies as a costly alternative has been changed due to the improvement
and enhanced energy-efficient processes. This has led more and more governments to invest
in desalination technologies as an attractive option to alleviate the water supply/demand gap
amongst their communities. (The National Academy of Sciences, 2008).
However, the costs of desalination, like the costs of water supply alternatives, are locally
variable and are influenced by several factors (The National Academy of Sciences, 2008).
These costs vary according to the desalination technology, the size of the plant and the cost of
the energy input to the plant (ACE, 2008). Moreover, the salinity of the feed water might be
an influencing factor of the costs of desalination (Craig, 2010). So far, the present trends
have shown that the oil-rich states particularly in the Gulf region kept in investing in
thermal/distillation technologies like MED and MSF technologies. (DHV Water BV et al.,
2004). This continued trend in investment in thermal processes is due to high salinity and
organic constitutes of seawater in the Arabian Gulf and the large plant capacities needed to be
met in such poor availability of fresh water resources in these countries. Moreover, and above
all, the low costs associated with energy input due to being one of the oil richest areas around
the world (Craig, 2010). Reverse osmosis (RO) technologies prevail where higher energy
costs are present due to the lack of the available local energy sources (DHV Water BV et al.,
2004).
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3.2.2 Cost of Desalination
The capital and operating costs of desalination plants have decreased significantly in real
terms, over the last decades. This is due to several factors, such as process design and
manufacturing improvements, increased competition and privatization (DHV Water BV et al.,
2004). Historical data show that production cost of desalinated water using thermal processes
has dropped from US$9.0/m3 to US$0.7/m3. While the costs associated with reverse osmosis
processes has dropped from US$1.55/m3 to US$0.53/m3 (Craig, 2010).
Figure (3-13): Cost Analysis of RO Desalination Plants over Years (Banat, 2007)
3.2.2.1 Capital and Operating Costs
The cost of a desalination plant comprises of both capital and operational costs. The capital
costs of a desalination plant include direct and indirect costs that fall into the following
categories (Banat, 2007):
• Direct costs that include but not limited to: land costs, construction costs, equipment
purchase and installation and the pre-treatment costs of feedwater.
• Indirect costs that include but not limited to: project management and overhead costs,
interest rates, insurances and contingency costs.
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After the establishment of the desalin